One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to determine when to plant tithonia by reviewing the USDA zone info for Tomball.

Planting Calendar for Tithonia

Frost tolerance for tithonia:	Not tolerant of frost.
When to plant:	After the last frost.

Since tithonia require warm weather you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant tithonia in Tomball is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant tithonia and expect a good harvest is probably September. Any later than that and your tithonia may not have a chance to really do well. Starting your tithonia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Tomball. In the coldest months of winter you can expect an average low temperature of 20°F.

Since the USDA zone info for Tomball is an average the actual date of last frost is different every year. Since half of the time in Tomball you get a frost after February 15 be ready to protect your tithonia if you have a late frost.

USDA Zone Info for Tomball

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Tomball

You may be interested in your other planting guides for Tomball.